EGCG-decorated zein complex particles: Relationship to synergistic interfacial properties

In recent years, polyphenol modules have been of widespread interest for regulating and manipulating the surface structures of protein, which in turn, rationally dominate their functional properties. In this study, the influence of epigallocatechin gallate (EGCG) on the microstructures and interface rheological behaviors of zein nanoparticles tuned by two different fabrication methods was described. As illustrated, embedded polyphenols not only significantly affected the surface properties of zein nanoparticles, but determined interfacial behaviors by regulating assembly methods and complex ratio, among which the method of surface decoration contributed greatly to improving surface hydrophilicity for zein-EGCG complex particles (ZEPs), also providing stronger interaction between zein and EGCG. Besides, Langmuir-Blodgett dilatational rheological study revealed that the ZEPs fabricated by EGCG surface decorating after zein nanoparticles formed (named ZEPs-2), exhibited superior surface-activity and higher interfacial stability compared with the anti-solvent zein/EGCG complex particles in ethanol/water solution together (named ZEPs-1), followed by the more prolonged adsorption and rearrangement time on the air-water interface. In addition, the ZEPs-2 presented a relatively larger desire to stabilize Pickering emulsions, especially in the EGCG concentration by 4 mmol/L. Generally, our findings not only provided simple methods to fabricate the ZEPs, but also unlocked a well-way to exploit anti-solvent decoration methods for various applications in the food industry.